/* 百度地图热力图js */
export default function loadHeatmap(ak) {
    return new Promise(function(resolve, reject) {
      if (typeof Heatmap !== 'undefined') {
        resolve(Heatmap)
        return true
      }
      let script = document.createElement('script')
      script.type = 'text/javascript'
      script.src = '//api.map.baidu.com/library/Heatmap/2.0/src/Heatmap_min.js'
      script.onerror = reject
      document.head.appendChild(script)
    })
  }
  